Faculty Publications
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Publications by NITK Faculty
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Item A tri-band slot antenna loaded with split ring resonators(John Wiley and Sons Inc. P.O.Box 18667 Newark NJ 07191-8667, 2017) Paul, P.M.; Kandasamy, K.; Sharawi, M.S.A compact tri-band slot antenna with independent tuning capability of its resonant frequencies is proposed in this article. A microstrip line fed square slot is loaded with split ring resonators (SRR) to obtain multiband characteristics. The slot is designed to resonate at 2.6 GHz. Two SRRs with single and multiple splits are loaded with the slot, which provide additional resonances at 4.3 and 4.7 GHz, respectively. Parametric analysis of the antenna shows that its resonance frequencies are controlled independently. The proposed antenna is fabricated on an FR4 substrate with a size of 60 × 60 × 1.56 mm2. The proposed design offers stable omnidirectional patterns and >3.8 dBi at all the resonating frequency bands. © 2017 Wiley Periodicals, Inc.Item A triband circularly polarized strip and SRR-loaded slot antenna(Institute of Electrical and Electronics Engineers Inc., 2018) Paul, P.M.; Kandasamy, K.; Sharawi, M.S.In this communication, a simple and compact multiband circularly polarized (CP) slot antenna loaded with metallic strips and a split-ring resonator (SRR) is proposed. The multiband operation is obtained via exciting the SRR and copper strips by the microstrip-fed square slot antenna. The SRR resonates at 1.83 GHz, while the strips and the slot antenna provide resonances at 2.5 and 3.1 GHz. Resonant modes of loaded SRR and strips combined with the fundamental mode of the slot produce CP waves at the resonance frequencies of the proposed antenna. The proposed antenna allows for independent tuning of different bands via the use of the tilted strips and the SRR. Also, the sense of polarization at the resonance frequencies can be controlled by changing the orientation of the strips and the SRR with respect to the slot. The proposed antenna is fabricated on an FR-4 substrate of dimension 50 × 50 × 1.56 mm3. Antenna performances in terms of 10 dB return loss bandwidth, 3 dB axial ratio bandwidth, gain, and efficiency are validated experimentally and are in a good agreement with the simulated results. © 2018 IEEE.Item A corner expanded slot antenna loaded with copper strips for dual-band circular polarization characteristics(John Wiley and Sons Inc. P.O.Box 18667 Newark NJ 07191-8667, 2020) Paul, P.M.; Kandasamy, K.; Sharawi, M.S.In this article, the design and implementation of a dual-band circularly polarized (CP) microstrip line fed square slot antenna with compact size is proposed. The proposed CP antenna consists of a square slot antenna with a pair of symmetric rectangular extensions on opposite corners and loaded with an array of inclined and truncated rectangular copper strips. The square slot with diagonal extensions resonates at 2.24 to 2.62 GHz with a 3 dB axial ratio (AR) bandwidth of 15.7%. Besides, loading it with an array of inclined and truncated rectangular copper strips helps produce a resonance at higher band with CP. The higher band operates between 3.26 and 5.18 GHz and centered at 4.52 GHz, with a 3 dB AR bandwidth of 45.5%. The polarization sense and resonant frequency of the proposed antenna can be independently tuned depending on the position and dimensions of the slot and strips, respectively. The proposed antenna is fabricated and measured in terms of impedance bandwidth, axial ratio bandwidth, peak gain, and radiation efficiency. Good agreement between the simulations and measurements of the prototype is obtained. © 2019 Wiley Periodicals, Inc.Item Characteristic mode-based compact circularly polarized metasurface antenna for in-band RCS reduction(Cambridge University Press Journals_subscriptions@cup.cam.ac.uk, 2020) Tharehalli Rajanna, P.K.; Rudramuni, K.; Kandasamy, K.This paper presents a novel design of a low profile circularly polarized (CP) metasurface (MTS) antenna with in-band radar cross-section (RCS) reduction property. The MTS is loaded as a superstrate on slot antenna and it can be viewed as a polarization-dependent MTS (PDMTS). The rectangular patch-based PDMTS is analyzed using characteristic mode analysis to find two orthogonal degenerate modes, which produces CP waves. Linearly polarized slot antenna is used to excite the PDMTS. The performance of PDMTS loaded slot antenna is analyzed numerically using full-wave analysis method. The PDMTS CP antenna is fabricated and its performance is tested experimentally. The proposed antenna has a compact structure and it has an overall size of (where is the free space wavelength). The measured results show that the PDMTS antenna achieves impedance bandwidth of 29.41, 3-dB axial ratio bandwidth of 9.05, broadside gain of 6.34 dB, and monostatic RCS reduction of at the resonant frequency of 5.86 GHz. The simulated results are in well agreement with the measured results and it is well suited for C-band Radar and Satellite communication. © © Cambridge University Press and the European Microwave Association 2019.Item An electronically switchable UWB to narrow band antenna for cognitive radio applications(John Wiley and Sons Inc. P.O.Box 18667 Newark NJ 07191-8667, 2020) Jacob, N.; Kulkarni, M.; Kandasamy, K.Cognitive radio (CR) is designed to achieve intelligent spectrum sensing and sharing, in order to solve spectrum underutilization problem. Conventional CR uses multiple/multiport antenna to switch between UWB and narrow band (NB) frequencies for primary and secondary users. In this article, we propose a compact frequency reconfigurable single port antenna using PIN diodes, to switch between UWB and NB frequencies. A circular disc monopole antenna with partial ground plane is designed to deliver UWB response. Three interdigital capacitors (IDC) are electrically connected to a partial ground plane and feed line using PIN diodes. OFF condition of all PIN diodes will provide the UWB response of 2.8 to 10.6 GHz and ON condition of the diodes will result in 36 different NB frequencies, completely covering the UWB spectrum. A simulation study carried out by incorporating a varactor diode into IDC, clearly shows that, the antenna resonance can be switched using PIN diodes and each resonant frequency can be fine-tuned independently, with in the band of interest. This is the unique feature of proposed antenna, which facilitates the technology for CR based internet of things applications in 5G wireless communication networks. © 2020 Wiley Periodicals, Inc.Item An Autonomous Frequency Reconfigurable Antenna Using Slotline Open-Loop Resonators(Institute of Electrical and Electronics Engineers Inc., 2021) Polaiah, G.; Kandasamy, K.; Kulkarni, M.This paper presents a slotline open-loop resonators based frequency reconfigurable antenna with autonomous switching of frequency bands. The dual-port slot antenna is designed to operate at 2.1 GHz when excited at port-1, and when port-2 is excited, the antenna can be reconfigured to operate at 2.85 GHz and 5.52 GHz, respectively. Port-1 is used to receive the control signal, which is converted to a DC signal using a rectifier. The rectified control signal is used to switch the operating frequency bands of the port-2. The proposed antenna configuration gives the flexibility of remote/wireless control of the operating frequency. The antenna prototype is fabricated and measured for observing the frequency switching at port-2. The measured results show that the antenna has been effectively switched from lower band frequency (2.8 GHz) to upper band frequency (5.41 GHz) when the PIN diode is ON. The proposed antenna in its final configuration can be potentially suitable for transmitter reconfigurable antenna without the need for external DC bias voltage. © 2021 Institute of Electrical and Electronics Engineers Inc.. All rights reserved.Item Circularly polarized rectangular dielectric resonator antenna with elliptical aperture feed for 5 GHz ISM band(John Wiley and Sons Inc, 2021) Usha, L.; Kandasamy, K.In this article, a new elliptical slot aperture feed circularly polarized (CP) rectangular dielectric resonator antenna (RDRA) has been proposed. The nonresonant slot excites two spatially orthogonal resonant frequencies in RDRA to produce CP waves. TEx111 and TEy111 are the orthogonal modes produced by the 450 inclined elliptical slot with respect to microstrip feed. Also, the sense of polarization at the resonance frequencies can be controlled by changing the orientation of the slot. The antenna performances in terms of impedance bandwidth, 3-dB axial ratio, and gain are validated experimentally. The proposed antenna can be used in 5 GHz ISM band for WiFi/satellite communications. © 2021 Wiley Periodicals LLC.Item Slot coupled dual band high gain circularly polarized metasurface antenna(John Wiley and Sons Inc, 2022) Tharehalli Rajanna, P.K.; Rudramuni, K.; Kandasamy, K.This article presents a slot coupled dual-band metasurface (MTS) based antenna with high gain and circular polarization characteristics. The MTS consists of two different unit cells, which give rise to two operating bands. The metasurface is excited by the slot aperture fed by a 50 Ω microstrip feed-line. The circular polarization is achieved by the diagonally oriented rectangular patch-based unit cells on top of the square substrate. Two orthogonal modes of MTS are required to produce circularly polarized waves, and these modes are excited by the slot aperture. The proposed MTS-inspired antenna is fabricated and experimentally validated. The experimentally verified impedance bandwidth of 33.71% in the lower frequency band and 5.35% in the upper-frequency band is achieved. The measured 3 dB (AR <3 dB)axial ratio bandwidth of 6.22% and 0.98% with a peak gain of 8.89 and 6.32 dBic is achieved with respect to 4.8 and 6.4 GHz resonant frequencies. © 2022 Wiley Periodicals LLC.Item Dual Frequency Multi-Functional via-Less Leaky Wave Antenna Featuring Enhanced Frequency Sensitivity and Dual Beam Scanning Capability(Institute of Electrical and Electronics Engineers Inc., 2024) Majumder, B.; Vinnakota, S.S.; Goud Rangula, M.; Kandasamy, K.In this paper we present a dual band low cross-polarized periodic microstrip leaky wave antenna (LWA) based on the multi mode resonator concept (MMR). The structure is capable of frequency dependent backward dual-beam steering and fast forward beam scanning in the upper and lower operating band, respectively. A gap loaded microstrip line is used as a host transmission line to feed the combination of the periodic patch radiators on the top and the bottom etched slots leading to the generation of the forward and the backward space harmonics. The etched ring slots at the bottom surface of the structure are not only responsible for steering the beam in the backward direction in the bottom hemisphere in its upper band but also adds radiation diversity in the overall radiation mechanism in its two operating bands. The potential use of this antenna resides in its ability to produce in-plane fast forward beam steering suitable for autonomous vehicle navigation systems in its lower band and out-of-plane backward-symmetric dual beam steering in the upper operating bands, suitable for tracking in relay systems. © 2013 IEEE.